1-keto-3-butyl-4-hydroxy-1, 2, 3, 4-tetrahydroisoquinoline



tion will have utility asintermediates for use in 5 anesthetic properties. The new' compounds in Patented June 16, 1953 I V UNITED" PATENT OFFICE 1-KE'r0 3-BUTYL-4HYDROXY-rascal .TETRAHYDROISOQUINOLINE Glenn Ullyct, Philadelphia, Pa., assignor to =S'mith,'Kline & French Laboratories, Philadel phia, Pa., a corporation of Pennsylvania Serial No. 116,866 p 1 Claim. (01. 260-289) No Drawing. Application septcgnper gflg 1949" This invention relates to new chemical compounds and more particularlyto certain new and useful tetrahydrois'oduinoloni compounds.

New compounds "in accordance with this-inventhe preparation of compounds, morelparticularlycertain pyridine derivatives which will beuseful for-the preparation-ofcertain novel aminoalkoxyisoquinoline derivatives which have physiological properties, more particularly analgesic and local in accordance with this invention comprise compounds'having the fo1lowing'structure:

where R is a member of thegroup consisting oi hydrogen, alkyl groups having not-more thanten carbon atoms, a phenylgroup; and phenyl alkyl roups, th alk v por on. of hic has not ore- 25 than three carbon atoms BJ and B are members of the group consisting ofhydrogen, hydroxyl, methyl, methoxy, ethoxy, amino, acylamino having not in excess 0f-5 carbon atoms, and alkylamino having not in excessofB carbon 30 atoms, the said substituents being so chosen that the number of nitrogen atoms in the substituents. does not exceed 1. I

By way of illustration, compounds according to this invention may be exemplified by com- 85 pounds having the followi g Structures:

OHaNHU The compounds in accordance with this in vention will be prepared by rearrangementof a compound having the following structure NH te c RI! R!!! I For the preparation oi typical starting material having the above structure for the preparation of compounds according to this invention see Ullyot et al., Journal Organic Chemistry, vol. 10, pp. 429-4401 12945), United States Letters Patent No. 2,473',fl84, dated June 14, 1949, and Ullyot, Taylor, and Dawson;-Journal American Chemical goc ty, 70,1542 K1948) Desirably, in'proc'eedingior/the preparation of compounds in accordance-with this invention, compounds having theiabove structure will be caused to rearrange with the addition of an alkali, as, for example, sodium hydroxide, ammonia, or the like, to the solution of the compounds and also desirably by the application of heat to the solution whetheror not an alkali is included therein 5 )1 In proceeding one may start with a salt of the base, in which case procedure in the presence of an alkali will be necessary to initially liberate the base for rearrangement.

More specifically, in proceeding according to this invention the freebasasor salt, will be dissolved in a suitable solvent such-as; for example, water, aqueous alcohol, or iother suitable solvent.

When the proceduredscarried out with use of an alkali, such will :1 desirably be present in amount equal to one orzmore molar proportions.

If heat is applied, such may be applied at any convenient temperature up to about the boiling point of the solvent and when heat is applied the rearrangement willb e.. efiected in from about one to four hours. The product compound will usually separate as a solid or an oil and will be recovered by filtration or extraction with a solvent, such as benzene, chloroform, ether, or the like, and purified, when necessary, by any well known procedure. If the product does not spontaneously separate, its separation may be promoted by the addition of acid, or by extraction with a suitable solvent, such as ether, benzene, chloroform, or thelikew As further illustrative of procedure for the production of compounds according to this invention, an amine, whichmaybe obtained from its salt by proceeding with use Oi an alkali to initiallyliberate the freelowing structure base, ha ving the fol- R"? O R CH-O/ where R, R and R' Eire as defined above, is dissolved in a solvent to cause rearrangement to the product compound. j I I Again, for the preparation of compounds .embodying this invention, to a solution of a salt of an amine having the above formula in any suitable solvent. such as "water, aqueous ethanol, aqueous isopropanol, or the like, is added an alkalisuch as sodium hydroxide potassium'hydroxide, ammonia, or the like, and the resultingzsolutionallowed to stand at room temperature until rearrangement-occurs; If desired, and for a saving of time'it generally willbe desirable, the solutionor mixture of the amine 'salt and alkali may be heated to hasten the rearrangement.

When the rearrangementghas occurred, the rearranged productwill, in certain cases, separate from the solutionand may be readily recovered. Again, where the-rearranged product does ;not readily separate from the solution, separation may be accomplished by concentrating the solution-an'dcooling; I T

4 fis more specifically illustrative of the preparation *or compounds in accordance with this invention, theamine salt is dissolved in any conheated toa'convenient temperature, say 75 C.

Rearrangement will occur in about'l-3' hours, with separation from the hot solution of the rearranged product, which can be readily recovered by any convenient procedure. As has been indicated, if the rearranged product does not separate out when rearrangement has occurred, the solution or mixture may be concentrated and then cooledto effect separation of the rearranged product.

The amine starting material, since it has two asymmetric carbon atoms, except in the case when R is hydrogen, is capable of existing as two racemic forms and has four optically active forms. The method according to this invention applies to the racemic forms'andto the optically active forms. Thus, when the amine salt starting material is a mixture of racemic forms, the prodnot is obtained as a mixture of racemic forms.

Likewise, when the starting material is an indi- As specifically illustrative of procedure for the preparation of compounds according to thi invention:

Example 1 For the preparation of 4-hydroxy-1,2,3,4-tetrahydroisoquinolon-l Anal. calcd. for C9H902N: N, 8.58. Found: N,

Example 2 For the preparation of 4-hydroxy-3-methyl- 1,2,3,4-tetrahydroisoquinolon-1 21.4 grams of 1-amino-l phthalidylethane hye drochloride, a mixture of two racemic forms, was

dissolved in 100 cc. of water and 7 cc. of sodium hydroxide was added. The solution was heated to boiling for three minutes and then at 95 C. for three hours. On cooling, a crystalline product, which melted at 120-145 C. and which consisted of a mixture of two racemic forms, was isolated.

I In a similar experiment 10.7 g. of l-amino-lthe higher melting racemic form, isomer A, of melting point 292-295 C. were rearranged. The product obtained was the lower melting 4-hy droxy-B-methyl 1,2,3,4-tetrahydroisoquinolon-1, isomer B, which after recrystallization from ethyl alcohol melted at 161-163 C. a l

Anal. calcd. fOr C10H1102NI C, 67.78; H, 6.27; N, 7.91. Found: C, 68.22, 67.94;..H, 6.08, 6.18; N, 7.94, 8.04.

Rearrangement of l-amino-lephtha'lidylethane hydrochloride of melting point 222-232" C. dec., gave a product which after crystallization from methyl alcohol melted at 166.5-1775" C.

Example 3 For the preparation of 4-hydroxy-3-ethyl- 1,2,3,4-tetrahydroisoquinolon-1 NH a i H 3H-C2 -i at 65-75 C. for about four hours. The resulting crystalline precipitate wasremoved by filtration,

and the heating process was repeated. In this manner, a total of 411.8 g. of tetrahydroisoquinclone wa isolated in five. drops of crystals, and consisted of a mixture of two racemic forms which melted from about -165 C. Rearrangement of the higher melting amine hydrochloride, isomer A, of melting point about 265-269 C. dec., resulted in the lower melting tetrahydroisoquinclone, isomer B, which melted at 127-129 C. Rearrangement of the lower melting amine hydrochloride, isomer B, which melted around 237- 243 C. dec., gave the higher melting racemic form of the tetrahydroisoquinolon, isomer A, which melted at 184-185 C.

Example 4 For the preparation of 4-hydroxy-3-propyl- .l,2,3,4-tetrahydroisoquinolon-1 54 grams of l-amino-l-phthalidylbutane hydrochloride were dissolved in 250 cc. of water and treated with 35 cc. of 40% sodium hydroxide. An oil precipitated after the reaction solution was heated at about 75-85 C. for about five hours. This tetrahydroisoquinolone did not crystallize but was shown to be the desired product by dehydration to 3-propyl-1,2-dihydroisoquinolon-1 by dissolving it in concentrated sulfuric acid, heating the resulting solution on the steam bath for an hour, and pouring the hot solution onto ice. The resulting solid product was collected and crystallized from alcohol. This 3-propy1-1,2-

dihydroisoquinolon-l was obtained as colorless. (capillary) needles which melted at 129-130 C. It analyzed as follows:

Anal. calcd. for C12H13ON: C, 76.98; H, 6.95; N, 7.48. Found: C, 77.15, 77.04; H, 6.98.7.00; N, 7.62, 7.63.

Example 5 For the preparation of 4-hydroxy-3-butyl- 1,2,3,4-tetrahydroisoquinolon-1 21 grams of 1-amino-l-phthalidylpentane hydrochloride were dissolved in 250 cc. of water, and 11.2 cc. of 40% sodium hydroxide were added. The solution was heated at about 75-85 C. for three hours and concentrated with a current of air to about 75-100 cc. In this case, the desired product did not spontaneously separate, and it was necessary to add 6.61 cc. of concentrated hydrochloric acid. This caused a viscous oil to separate. This product did not crystallize, but it was shown to be the desired tetrahydroisoquinolone by dehydration to 3-butyl-l,2-dihydroisoquinolon-l according to the procedure used in the preceding example. The dihydroisoquinolone so obtained was recrystallized from.

N, 6.96. Found:

to pale yellowleaflets which melted at139l5 -l40.5

preparation of i-hydroxy-3-ethyl-6fldimethyl-l3,3,4etetrahydroisoquinolon-li T YQNH, I l.

CH3; W. I

This compound will be prep a red by heatingan alkaline solution of 1-amino-1-(5,6-dimethylphthalidyl) propane as the starting material, using the procedure described in Example 1.

Emample 7 For the preparation of -hydroxy-l-ethyl- 12,3,4-tetrahydroisoquinolon-1 Emmple ,8

. For the preparation of 4-hydrox y -3-propyl- 6,7-dimethoxy-l,2,3,4-tetrahydroisoquinolon-l Example 9 For the preparation of 4-hydroxy-3-ethyl-7,8- dimethoxy-1,2,3,4-tetrahydroisoquinolon-1 CHAO- This compound will be prepared by heating an alkaline solution of l-amino-1(6,7-dimethoxyphthalidyl) -propane as starting material using the procedure described in Example 1.

- --Ea:wmple-10 For the preparation of e-hydroxy-3-phenyl-7- ethoxy-1 ,2514-tctrahydroisoquinolon-1 -Q ci "5H 7 This compound will be prepared by heating an alkaline solution of amino- (6eethoxyphthalidyl) phenylmethane" as .starting material using the procedure described in Example 1.

a 7 Example 11 For the preparation of 4,6,7-trihydroXy-3- benzyl-1,2,3,4-tetrahydroisoquinolon-1 This compound will beprepared by heating an alkaline solution of 1-amino-1-(5,6-dihydroxyphthalidyl) -2-phenylethane as starting material using the procedure described in Example 1.

Example 12 CHI-02H;

I 'I hisjcqmpoundwas prepared bythe rearrangement of 1 amino-1-(fi-aminophthalidyl) -propane dihydrochloride, which in turn was prepared by the reduction of 1-(6-nitrophthalidyD-1- nitropropane as described below.. Thisstarting material, the dinitrophthalidylpropane in turn waspreparedin the following. manner, using generally the procedure of.Shriner and Keyser (J. Org. Chem., volume 5, 200 (1940)).

A solution of 22.1 girls. of l-nitro-l-phthalidylpropane,melting at 94- 96? C. in 20 ml. of concentrated sulfuric acid was added dropwise with stirring to. a mixture of 11 gms. of potassium nitrate and 33 ml. of concentrated sulfuric acid, the reaction temperature being maintained lower than 51 C. After stirring for three hours at less than 10 0., the mixture wasallowed to stand at room temperature for 16 hours and poured over cracked ice. The granular solid which separated was filtered and dried and melted at 93-96" C. Recrystallization from alcohol provided a product melting at -98 C. v

30 gms. of the above dinitrophthalidylpropane was reduced using cc. of glacial acetic acid and 0.1 gm. of platinum oxide at a temperature of-60,-80'. One hundred per cent. of the theoretical volume of hydrogen corresponding to the reduction of one nitro group was taken up in a period of 10 minutes. The hot solution was filtered and cooled, and the light orange product which separated and was collected, M. P.

1'78.-181 C. Digestion with hot alcohol and butanone gave a product,1 (6-aminophthal} idyll-l-nitropropane; melting at'182 i84 113 gms. of l-nitro-l-(fi aminophth'alidyl) propane was reduced using a, saturated aqueous solution containing one equivalent of hydro jchloric acid under 50: pounds per square inch pressure of hydrogen at 60 C. usinga palladium: on carbon catalyst. After removal of the catalyst the aqueous solution containing; i amin'o l- (6 -,ammophtha1iqy1) prop ane dihydrochloride was made definitely alkaline by the addition ot excesfs'40% ,sodium hydroxidesolution to efiect rearrangement to the corresponding isoquinolon. The resulting mixture was heated at 90? C'. under vacuum and 1.5 liters of water wasslowlydistilled for a period of six hours, Heating was then continued fora period of hours removing an additional250 cc. of water The darkmixture was then cooled to 10 and the solid was removed .i

by filtration. The dark filtrate was then acidifled and furtheniiltered to remove additional salt, and cooled over a long vperiod of time The yield was a white crystalline powder product 'jof 7-amino-;3-ethyl -4- hydroxy-1,2,3,4 -tetra-hydro-;

isoquinolon-l whichmelted at 216521779; 7 I

Example 1'3" 4-hydroxy-3-ethyl-7 acetylamino -1,2 ,3,4 tetrahydroisoquinolon-l o CHa-CO-NH H-CZHg s OH This compound is prepared from .lz-amino-l-ifiacetylaminophthalidyl) -propane dihydrochloride by rearrangement using thev procedure otExam resulting will besubsequently reduced using the procedure of Example 12 for reductionof 1- (fi-aminophthalidyl) -1-nitropropane.

Example 14 4-hydroxy-3-ethyl-7-butyrylamino -1,2,3,4-tetrahydroisoquinolon-1 I OH - This compound will be prepared by rearrange- 'butyric anhydride to effect N-butyrylation. The nitro group of the resulting butyrylamino compound is then reduced using the procedure of Example 12.

Thiscornpound is prepared by the reaii angemei 15 9f;" =16e meih m qphth i l ia i rbe a us he brocedure-or-E- mpm 12; The

s arting materiar'is"prepared from 1-.".-

(l-933). '1 fThe"'nitro group" of 'the "resulting 'di-J methylaminocompound' isreduced, to the" corres end n f 'ni or Example'1'2 Dhenyl 1,2,3,-4 tetrahydroe,

Ihyd oxy 3 isoquinolon- 4 This-compoundis prepared my rearranging- 4t aminophenylphthalidylmethane heny1phma1= I idylcarbinamine) by-the procedure ofExample s-ii iiny'i 112,3,4 tetrahydroisoouinolom1 To a solution of 1.0 g. of l-amino-l-phthalidylhexane hydrochloride in 25 cc. of warm water was added a solution of 0.4 g. of sodium hydroxide in 5 cc. of water. The resulting mixture was heated just below reflux for 20 hours. The oil which separated was taken int chloroform and the chloroform was removed by distillation in vacuo. The white, solid which remained was shown to be the desired product in the following way. The solid was dissolved in 7.5 cc. of concentrated sulfuric acid and this solution was heated at 75 for 35 minutes. It was then cooled and poured into cracked ice. was removed by filtration, washed with water and recrystallized three times from isopropanol, melting at 106.5108. As illustrative of theme of the novel compounds in accordance with this invention, they may, for example, be used as intermediates for the formation of corresponding pyridinederivatives by dehydrating them, for example, by heating them at 'a temperature above their melting compoiind using the procedure The white solid I amas 1 1 points and below their decomposition points, or by treating them with-a dehydrating agent, such as sulfuric acid, phos'phoruspentoxide, or the like. More specifically, the dehydration 0f ;t he 4minpounds according to this invention may be effected by dissolving in a solvent, such as benzene, and heating with a dehydrating agent,isuch as KHSO4 at a temperature oi 2M0 C;,,or;in the alternative, variously by heating to a temperature of 10 C.100 Ciabove the melting point, depending upon the particular compound.

plication for U. patent flledby me. August 17,

1946, Serial No. 691,394, now" abandoned. Y

Thegoperative derivatives produced by the use of the compounds according ,to this invention will be produced as intermediates, more particularly by. dehydrating v.the compqunds in accordance with this invention and will be usedjor the production of corresponding aminoalkoxyisoquinoline derivatives having physiological properties, as analgesic and local anesthetic properties, by treating-them with a reagent; as, forexample, phosphorus oxychloride, to produce-the cori'esponding l-chloroisoquinoline derivatives and reacting such derivatives with an amino alcohol of the formula YROH Where Kisatertiary nitrogen-linked amino group including a member of the group consisting of aliphatic groups of not over ten carbon atoms; a ,py,ridine group and where N is a mempei of thegroup containing not more than six carbon atoms;

More specifically, the intermediates produced by:the;.dehydration oi-icompounds inaccordahce with this invention will beconverted to'the 1- chloro derivatives'byheating under reflux until the evolution of hydrogen chloride ceases. The excess oxychloride is then removedby distilla- 12 in and. the product, p rifi xfldis lat on vacuo. 4 'Ihel' chlorode ivatives are then treated with an' alkali metal'derivative of anamino l q q Q i hefiv e in a b adding t e, ,1- chloro derivative toa suspension or solution of the alkali metal derivative; of the amino alcohol. the ie wbei mad ep silw i s r ina fellowedby heating, with continued :stirringfto a temperature up to the boilingpoint -ofthe solvent. Qncompletion of thereactionthe reaction mixe'i s e dendi va orsi d tor m ve e ise m metal lq id th sol ni' e i ird etillat'ion and. the aminoalkoggyisoquinoline derivative purified by distillation in vacuo, all as more specifically d isc1osed' in application for United States patent filed by me August 20, 1948, Serial No. 45,432, now abandoned. g

This application is a continuation-in-part of application filed by me August 17 1946, Serial No. 691,393, now abandoned.

The method disclosediier'ein for making compounds claimed herein is thesubject matter of a copending application' filed by me September 20, 1949', Serial No. 116,868, now Patent No. 2,538,342, issued January 16, 1951. 7 e

What is claimed is: A compound having the structure:

GLENN E. ULLYOT.

40 Chemie (4th Ed), vol. XXI, page 582 (1935).

I Gabriel 61; 2.1.. Brichteff V01. 33, pp. 980-1000 Ullyot et alL-J. Org. Chem, vol. 10,'pp. 429- 

